Hack-saw



(No Model.)

L. S. STARRETT.

.HACK SAW.

No; 576,626. P6 66666 P66. 9, 1697.

. if 0 G 11 F g-Z (m WITNESSES- Jmwz C? m ig- UNITED STATES- PATENT QFFICE.

LAROY S. STARRETT, OF ATHOIJ, MASSACHUSETTS.

HACK-SAW.

SPECIFICATION forming part of Letters Patent No. 576,626, dated February 9, 1897.

Application filed May 28, 1895. Serial No. 551,022. (No model.)

To wZZ whom it may concern:

Be it known that I, LAROY S. STARRETT, of Athol, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Hack-Saws, of which the following, taken in connection with the accompanying drawings,is a specification.

The primary object of this invention is to improve the construction of hack-saws in respect to the ready insertion and removal of the saw-blade and the firm holding of its ends upon their studs while in use by means of spring-pressed plungers which overlap such ends, but yield longitudinally when required.

Another object is to make the back or frame more readily adjustable to saws of different lengths by means of spring-actuated pawls engaging automatically in notches in the edge of the frame, which in such cases is made in two parts, and a further object is to strengthen the connection of the frame and its wooden handle by a novel arrangement of the tightening-nut.

The ends of the saw-blade in either rigid or extensible frames engage transverse studs at the inner ends of bearings or holders mounted in sockets at the extremities of the frame, one of the holders being the inner end of the frame-shank. These end holders are longitudinally recessed to receive a spring and a movable plunger actuated thereby. The tip of the plunger is beveled and overlaps the end "of the saw to keep it engaged with the stud, but is readily pressed back against its spring when the saw is to be released. A transverse pin in the holder enters a longitudinal groove in the plunger and prevents its rotation or loss. Such pin also projects enough to prevent the holder from dropping out of the frame-socket.

My invention includes a saw frame or back made in two parts connected extensibly bya rigid sleeve or coupling and a spring-actuated pawl pivoted on said coupling at either or both ends and engaging at its tip in notches in the frame. The couplingis cut away or the heel of the pawl raised near the spring, so that a slight pressure will disengage the pawl from its notch when the frame is to be shortened; but it engages automatically in elongating the frame and holds firmly without any attention by the operator. The saw-blade prevents the members of the frame from pulling out of the coupling-sleeve. After adjustment in the frame the saw-blade is strained to tension by turning the wooden handle around the threaded metal shank of the frame, the handle having a cylindrical nut arranged transversely in it with its threaded perforation in position to engage said shank. A coiled spring surrounds the shank within the handle.

I employ the studs and spring-plungers for detachably securing the saw ends, and also the transverse cylindrical nut for, the handlefastening, as well in my rigid-framed saws as in those made extensible. I therefore do not limit my claims for the saw-fastening and handle-fastening by the character of the back of the frame.

In the drawings, Figure 1 is a side view of one of my extensible saws, part of the sleeve or coupling being broken away to show the spring-pawl and notches. Fig. 2 is an enlarged longitudinal section through the handle and connected parts. Fig. 3 is an enlarged transverse section on line 3 3 of Fig. 1.

A represents'the frame or back of the saw (shown in Fig. 1 as made in two parts) separable within the flattened sleeve or coupling B, so as to lengthen or shorten the frame as a whole, to provide forsaws of different lengths, as heretofore. The sleeve may be permanently secured to one member of the frame, but I prefer to make it adjustable with relation to both members, as indicated in Fig. 1.

The sleeve or coupling B may be a flattened tube, but I have herein represented it as U- shaped, that is, open along its inner edge toward the saw-blade C. At each end of such inner edge a strong pawl D is mounted on a pivot E to engage with notches ain the inner edge of the frame-section A. A fiat steel spring F projects rearwardly from the heel of the pawl and slides freely along the frame edge, serving to engage the tip or toe of the pawl automatically in the notches a. The edge of the coupling-sleeve is shown cut away, so that the heel of the pawl may be depressed to release its toe from the notch when the frame is to be shortened. By making both members of the frame adjustable in the coupling-sleeve such sleeve may be always central and the tool thereby made more symmetrical.

The ends of the frame stand about perpendicular to the back, and at their extremities are formed with cylindrical sockets G in line with each other axially to receive the sawholders H I. The holder H is a part of the shank II of the frame on which the operating-handle is mounted, and the holder I is a cylindrical plug having an end flan go 2' to prevent it pulling through its socket. These holders are out half away at their inner ends to give a fiat central seat for the end of the saw 0, and a short transverse stud K is fixed in position to enter the circular eye at the saw end. A longitudinal recess is formed in each holder to receive a spring L and a movable plunger M, pressed forward thereby to overlap the end of the saw and keep it from becoming disengaged prematurely; but it is readily pressed back when the saw is to be detached. The tip of the plunger is preferably beveled back toward the flat face of the holder to readily slide over and fasten the saw. A pin N through the holder enters a groove in the plunger and prevents it from turning. It also retains the holder in its socket G while permitting a longitudinal movement to holder and plunger.

I provide for turning the saw-blade with its cylindrical holders, so that it may stand perpendicular to the plane of the frame when desired. Tension on the saw is relaxed, and

the holder H is turned ninety degrees to right or left by means of a milled knob O, fixed on said holder between its bearing G and the handle P. A slight projection or rib R is formed on this knob and on the end cap of the holder I, and corresponding notches are cut in the outer edges of the sockets G. Engagement of these parts holds the saw in its desired position. A coiled spring Q is introduced within the ferrule bet-ween the knob O and handle I, such spring tending to keep the ribs R in their notches. A longitudinal movement of the holders H I with the handle P and independently of the knob O is pro- 1 vided for by this spring and by a groove in the shank II, which receives the tip of the screw 0, allowing the shank or holder to move through the knob O.

The outer end of the shank II is threaded for attachment to the handle I. The nut S, which engages this threaded part, is cylindrical and is inserted transversely through the handle. (See Fig. 2.) Great strength is secured by this arrangement, and there is no possibility of the nut being pulled inwardly from its seat, as would be liable to occur in tightening the saw with the nut at the axis of the handle.

I claim as my invention- 1. In a hack-saw, the back or frame having terminal sockets G G, alined with each other and with the saw-blade, and holders II I therein, provided with studs K to hold the ends of the saw C, in combination with spring-pressed plnngers M working in longitudinal recesses in the holders and overlapping the saw ends to prevent premature detachment, substantially as set forth.

2. The saw-frame and its alined sockets G, and the saw end holders and fasteners described, consisting of the parts II I cut away to the axis and provided with the studs K, to afford a flat seat and firm holder for the sawblade, in combination with the reciprocating plunger )1, beveled at its tip where it overlaps the saw end, the spring L held in a recess in the parts II I and acting on the plunger M, and with the transverse pin N entering a groove in the plunger to keep it from rotation but permit longitudinal movement, substantially as set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this 13th day of May, A. D. 1895.

LAROY S. STARRETT.

iVitn esses:

A. II. SPENCER,

JOHN G. KENNEDY. 

